July 14, 2015
Canada's canola meal could become a popular choice of feed ingredient worldwide if critical scientific approaches could obtain the undiscovered nutritive power of dietary fibre, according to Dr. Bogdan Slominski of the University of Manitoba.
He was speaking at the International Rapeseed Congress held in Saskatchewan, Canada, during July 5-9.
The aforementioned approaches include breeding for top-quality yellow-seeded canola, utilising new dehulling options and harnessing the potency of new multi-carbohydrase enzyme formulations which could break down fibre and improve nutrient utilisation for monogastric animals such as pigs and poultry.
"The more we understand about the composition of dietary fibre and the options to address it, the more success we can achieve to benefit producers, industry and the end-use customer," Dr. Slominski added.
While canola meal has a good protein content and amino acid profile among a handful of positive attributes, Dr. Slominski emphasised the importance of dietary fibre that presents an 'X-Factor' influencing nutritional value, processing approaches and feeding strategies. In addition, research had revealed that canola meal possesses a high level of dietary fibre.
"This is a consequence of the small size and also the high oil content of canola seed, which is roughly 42 to 45 percent. In fact, the neutral detergent fibre and total dietary fibre values of canola meal are higher than those of soybean meal," Dr. Slominski explained.
Dietary fibre can be raised by specific processing methods including pre-press solvent extraction and the employment of desolventizer-toaster. Currently, the content of neutral detergent fibre (NDF) and total dietary fibre (TDF) of canola meal averaged 29.6% and 38% dry matter (DM), respectively, based on recent surveys in Canada.
Dr. Slominski also talked about the newly developed yellow-seeded B. napus canola and canola-quality B. juncea mustard that boast outstanding attributes but offer lower dietary fibre. Interestingly though, similar growth performance parameters were observed in broiler chickens and turkeys fed with conventional canola meal and soybean meal, when diets were formulated based on digestible amino acids and available energy contents.
This, Dr. Slominski remarked, shows that all forms of canola meal could substitute soybean meal in poultry rations. "The development of low-fibre canola would result in quantitative changes as evidenced by increased oil, protein, and sucrose contents, rather than qualitative changes due to decreased fiber content," he added.
In hull removal, when evaluating the meal from the tail-end dehulling process using sieving technology, a significant increase in protein content of dehulled versus standard meal, from 36.8% to 42%, were seen. In addition, there was also a substantial reduction in the content of dietary fiber, from 30% to 21.4%.
But there was no difference in growth performance when diets were balanced for major nutrients and fed to young broiler chickens and weaned pigs. It led Dr. Slominski to conclude that most of the canola fibre is "simply a diluent with little effects on nutrient utilisation.
Still, more nutrients could be garnered from indigestible fibre through new and more effective methods of feed enzyme formulations.
"Recent studies show that substantial gains in nutrient utilisation are possible for all species with properly formulated and applied enzyme supplementation," Dr. Slominski said. "This approach can make feasible the use of full-fat canola or off-grades of canola seed that can represent an economic, well-balanced source of protein."
In addition, research trials by Slominski and other parties indicated that multi-carbohydrase formulations are more effective than single enzymes.
Fibre components of canola meal, including non-starch polysaccharides (NSP) and glycoproteins, may serve as substrates for multi-carbohydrase enzymes and support the release of additional energy, Dr. Slominski explained. This is demonstrated by an apparent rise in metabolisable energy (AME) of 100-150 kcal/kg of canola meal.
Thus, multi-carbohydrase technology is at the forefront of scientific knowledge on the most effective employment of feed enzymes, Dr. Slominski stated. "It leverages what we have learned from years of research to offer a much more comprehensive and sophisticated option than traditional approaches."